$\begingroup$@NKCampbell Since the two answers here are more informative, and the top one has double the votes than the answer there, you should really close that question as duplicate of this one. It doesn't matter which was asked first.$\endgroup$
– uhohApr 18 at 0:08

$\begingroup$I assume there was no air lock on the CM, so did these EVAs require emptying the CM of air?$\endgroup$
– Tor KlingbergApr 17 at 10:15

2

$\begingroup$@TorKlingberg - So it would seem. From the History of Deep Space EVA link above: "After depressurizing the cabin and performing suit integrity checks, the CM crew hatch..."$\endgroup$
– T.J. CrowderApr 17 at 10:30

In addition to the scheduled EVAs on the later Apollo missions, if the lunar module was unable to securely dock with the command module after returning from the moon, the commander and lunar module pilot could have EVA'd back to the CM. This procedure was never required during the program. (The Soviets' tiny 1-seat lunar lander, the LK, had no docking hatch, and EVA was the normal way to get between it and the LOK mothership!)

$\begingroup$Exactly. I seem to recall we've answered this question before. In fact, it was Deke Slayton himself who ordered that it be made possible, and thus the wrench to open the CM hatch was added to the LM repair kit.$\endgroup$
– DrSheldonApr 16 at 21:41

4

$\begingroup$Given that it was possible to open the hatch from the inside for the EVAs that actually happened, seems like you'd only need a wrench if the guy in the CSM was incapacitated. quora.com/… points out that if you did this, your "incapacitated" and thus presumably un-suited CSM pilot would become a dead CSM pilot. Still, the other two potentially make it home.$\endgroup$
– Chris StrattonApr 16 at 23:16